What will happen when yearly subscription is over?

Almost one year ago I got one year subscription for Office 365. What will happen after a year if I do not buy new sub? Will I still be able to use Office products on my 3 PCs or will they just stop working? I know I will loose additional 20gb on Skydrive and Skype landline calls.

They will keep working as viewers. You won't be able to edit documents. So, no, they will stop working.

I've never dealt with an expired Office 365 installation, but I would've expected this. I know that this is exactly what happens when a trial version expires. We have customers that contact us because "My Office quit working. I can't change anything!" What usually happened is that they got a new computer with a 30 day trial of Office. When it expires, it changes to read-only.